Ketamine/midazolam versus fentanyl/midazolam procedural sedation for interventional radiology: A prospective registry
Greco GF, Al-Asadi Z, Belcher AM, Mattox E, Korona MV, Deipolyi AR. J Vasc Interv Radiol. 2025 Feb 3. doi: 10.1016/j.jvir.2025.01.050. ePub ahead of print.
Read the full article on JVIR.
Tell us about you, your team and your institution.
Amy R. Deipolyi, MD, FSIR: I work in Charleston, West Virginia at a tertiary care center called Charleston Area Medical Center (CMC). It's an academic institution that's affiliated with West Virginia University (WVU), so half of the WVU medical students rotate in the hospital. It's 1,000-bed facility, a level one trauma center, a stroke center and has a cancer center. It essentially serves the bottom half of the state. The hospital didn’t have a dedicated IR service line until 4 years ago when I was recruited to bring IR to the community. I started working within the vascular surgery section, and then eventually separated off as our practice got busier.
Why did you and your team choose to pursue this topic? What gap in current IR practices were you aiming to address?
AD: Traditionally, IRs use moderate sedation with fentanyl and midazolam for procedural sedation.
I think that there are a few things to take into account when it comes to moderate sedation versus ketamine. For example, some patients have more experience with opiates, given the opiate epidemic, or cancer patients use narcotics for pain relief. As a result, moderate sedation is less effective over time on a population level. Additionally, I think that patients have an expectation about what they're going to undergo when they get a procedure. If you’re told you’ll be awake for a colonoscopy, you’d probably ask for propofol, which is the standard of care these days.
There are times when I've given the maximum amount of sedation and if I'm in the middle of a procedure, I can't safely stop what I'm doing, even if the patient is uncomfortable. It leaves you feeling very uncomfortable for harming the patient--even though you try to help them with their clinical problem, you feel like you've done harm by exposing them to a traumatic incident.
I was talking about this to an ER physician colleague who asked why we don’t give ketamine, which is routinely used in the ER. I investigated it more, and it turned out that my hospital has a deep sedation policy. It outlines who can get deep sedation privileges and the steps to doing that. I went to the sedation committee and advocated for us, and they approved IRs to be added to the privileged provider types. In addition, we started this research project, which was essentially a quality assurance and quality improvement project.
We had a form that nurses would fill out documenting pain scores before, during and after the procedure. They’d also document any complications that we encountered. We collected a couple of hundred moderate sedation cases.
When we got privileges, we switched completely over. So, anyone that would have received fentanyl versed now got versed ketamine. We continued to collect data, and soon had enough to clearly show patient benefit. Patients who got ketamine had less pain during and after the procedure. It was successful, and it wasn’t dangerous. We had one respiratory event in the fentanyl versed group and none in the ketamine versed group.
With its success, we decided to publish a paper to share our experience, and hopefully inspire other IRs to think about their practices and how to make the patient experience better.
How have the key takeaways from your study influenced sedation protocols in IR moving forward?
AD: One thing that was asked by the reviewers is, how do you quantify a pain score with ketamine when the patient is asleep? In those cases, we document as a zero. If you're unconscious, you're not experiencing any pain.
What was most notable was that the pain scores were significantly lower after. That's been shown already in surgical literature. If you go to the operating room for a big surgery and get ketamine in your cocktail, you're going to require and ask for fewer narcotics after the procedure.
Ketamine is an old drug, but it's coming back into the discussion for treating depression, PTSD and chronic pain. It has a more prolonged effect on pain, and patients report less pain after the procedure. In terms of delivering a good patient experience, they’ll leave with less pain for hours to days afterward.
Were there surprising observations related to workflow, patient comfort or staff confidence with using ketamine without anesthesia providers?
AD: People are so used to the moderate sedation with fentanyl versed. Whenever you're instituting change, there's always a fear or resistance. Since ketamine is a scheduled drug that's usually only given by anesthesiologists, people are intimidated to use it.
There is an element of safety with ketamine, because the fentanyl midazolam combination will lower your oxygen saturation and blood pressure. There's a lot of cancer patients where the saturations in their blood pressure are borderline, so we can't even give them anything. Ketamine is a better option because it does not decrease your breathing or blood pressure.
The other benefit of ketamine is that it has extended what we can do without anesthesia. IV drug users get abscesses, but you can't get them sedated with moderate sedation. Most of the time we can give them ketamine and get them through without requiring anesthesia for a 10-minute drainage. Every patient has an optimal combination that will work for them, and ultimately, we’re able to offer options.
It's surprising how quickly we realized the benefits of ketamine. Part of the study was a brief survey about how effective you think moderate sedation is, before being prompted several months later about how effective deep sedation is. The last question is the most telling: we asked everyone what they would choose for themselves if they had to have an abscess drain. 85-90% said deep sedation with ketamine.
How might this research impact broader treatment decisions, clinical processes or training within IR?
AD: In the second phase of my career, my goal is to convince IRs across the country to get ketamine into their toolkit, but there are barriers. There's advocacy that must be done. So, I have shifted my entire focus. I've gotten grants to study this, and I want to publish this data to show how safe and effective it is. Then we can go and advocate as IRs to sedation committees.
What are your next steps or plans for follow-up research?
AD: We have received grants from SIR Foundation and the Radiological Society of North America (RSNA), which will fund randomized, single-blind studies where the patients enroll, and they don't know if they're going get moderate or deep sedation. We know, but we don't tell them. We’ll collect pain scores like we did for the other study but also give them a validated anesthesia questionnaire to assess satisfaction and other side effects.
I have an IRB approval, so we're about to open those studies. The SIR Foundation grant is supporting a study specific to abscess drainage, which of course is a very painful procedure a lot of times because the tissue is inflamed. The RSNA grant is looking at lung biopsies, specifically because lung biopsies are somewhat painful.
We did see a difference with ketamine in our observational study. Lung biopsies tend to come with a high complication rate, specifically lung collapse. So, if there are any changes in an adverse event profile, we're more likely to see it in something with a high complication rate such as that.
